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-rw-r--r--src/fftw3/rdft/rdft2-radix2.c479
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diff --git a/src/fftw3/rdft/rdft2-radix2.c b/src/fftw3/rdft/rdft2-radix2.c
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+/*
+ * Copyright (c) 2003 Matteo Frigo
+ * Copyright (c) 2003 Massachusetts Institute of Technology
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/* $Id: rdft2-radix2.c,v 1.1 2008/10/17 06:11:29 scuri Exp $ */
+
+/*
+ Compute RDFT2 of even size via either a DFT or a vector RDFT of
+ size n/2.
+
+ This file is meant as a temporary hack until we do the right thing.
+
+ The right thing is: 1) get rid of reduction to DFT, and 2) implement
+ arbitrary even-radix reduction to RDFT. We currently reduce to DFT
+ so as to exploit the SIMD code. We currently do only radix-2 in
+ order to avoid generating yet another set of codelets.
+*/
+
+#include "rdft.h"
+#include "dft.h"
+
+typedef struct {
+ int (*applicable) (const problem *p_, const planner *plnr);
+ void (*apply) (const plan *ego_, R *r, R *rio, R *iio);
+ problem *(*mkcld) (const problem_rdft2 *p);
+ opcnt ops;
+ const char *nam;
+} madt;
+
+typedef struct {
+ solver super;
+ const madt *adt;
+} S;
+
+typedef struct {
+ plan_dft super;
+ plan *cld;
+ twid *td;
+ int is, os, ivs, ovs;
+ int n, vl;
+ const S *slv;
+} P;
+
+/* common applicability function of forward problems */
+static int applicable_f(const problem *p_, const planner *plnr)
+{
+ UNUSED(plnr);
+ if (RDFT2P(p_)) {
+ const problem_rdft2 *p = (const problem_rdft2 *) p_;
+ return (1
+ && p->kind == R2HC
+ && p->vecsz->rnk <= 1
+ && p->sz->rnk == 1
+ && (p->sz->dims[0].n % 2) == 0
+ );
+ }
+
+ return 0;
+}
+
+static int applicable_f_dft(const problem *p_, const planner *plnr)
+{
+ UNUSED(plnr);
+ if (applicable_f(p_, plnr)) {
+ const problem_rdft2 *p = (const problem_rdft2 *) p_;
+ return(p->r != p->rio
+ || (p->iio == p->rio + p->sz->dims[0].is
+ && p->sz->dims[0].os == 2 * p->sz->dims[0].is));
+ }
+ return 0;
+}
+
+/* common applicability function of backward problems */
+static int applicable_b(const problem *p_, const planner *plnr)
+{
+ if (RDFT2P(p_)) {
+ const problem_rdft2 *p = (const problem_rdft2 *) p_;
+ return (1
+ && p->kind == HC2R
+ && (p->r == p->rio || DESTROY_INPUTP(plnr))
+ && p->vecsz->rnk <= 1
+ && p->sz->rnk == 1
+ && (p->sz->dims[0].n % 2) == 0
+ );
+ }
+
+ return 0;
+}
+
+static int applicable_b_dft(const problem *p_, const planner *plnr)
+{
+ UNUSED(plnr);
+ if (applicable_b(p_, plnr)) {
+ const problem_rdft2 *p = (const problem_rdft2 *) p_;
+ return(p->r != p->rio
+ || (p->iio == p->rio + p->sz->dims[0].os
+ && p->sz->dims[0].is == 2 * p->sz->dims[0].os));
+ }
+ return 0;
+}
+
+/*
+ * forward rdft2 via dft
+ */
+static void k_f_dft(R *rio, R *iio, const R *W, int n, int dist)
+{
+ int i;
+ R *pp = rio, *pm = rio + n * dist;
+ int im = iio - rio;
+
+ /* i = 0 and i = n */
+ {
+ E rop = pp[0], iop = pp[im];
+ pp[0] = rop + iop;
+ pm[0] = rop - iop;
+ pp[im] = K(0.0);
+ pm[im] = K(0.0);
+ pp += dist; pm -= dist;
+ }
+
+ /* middle elements */
+ for (W += 2, i = 2; i < n; i += 2, W += 2) {
+ E rop = pp[0], iop = pp[im], rom = pm[0], iom = pm[im];
+ E wr = W[0], wi = W[1];
+ E re = rop + rom;
+ E ie = iop - iom;
+ E rd = rom - rop;
+ E id = iop + iom;
+ E tr = rd * wr - id * wi;
+ E ti = id * wr + rd * wi;
+ pp[0] = K(0.5) * (re + ti);
+ pp[im] = K(0.5) * (ie + tr);
+ pm[0] = K(0.5) * (re - ti);
+ pm[im] = K(0.5) * (tr - ie);
+ pp += dist; pm -= dist;
+ }
+
+ /* i = n/2 when n is even */
+ if (!(n & 1)) pp[im] = -pp[im];
+}
+
+static void apply_f_dft(const plan *ego_, R *r, R *rio, R *iio)
+{
+ const P *ego = (const P *) ego_;
+
+ {
+ /* transform input as a vector of complex numbers */
+ plan_dft *cld = (plan_dft *) ego->cld;
+ cld->apply((plan *) cld, r, r + ego->is, rio, iio);
+ }
+
+ {
+ int i, vl = ego->vl, n2 = ego->n / 2;
+ int ovs = ego->ovs, os = ego->os;
+ const R *W = ego->td->W;
+ for (i = 0; i < vl; ++i, rio += ovs, iio += ovs)
+ k_f_dft(rio, iio, W, n2, os);
+ }
+}
+
+static problem *mkcld_f_dft(const problem_rdft2 *p)
+{
+ const iodim *d = p->sz->dims;
+ return X(mkproblem_dft_d) (
+ X(mktensor_1d)(d[0].n / 2, d[0].is * 2, d[0].os),
+ X(tensor_copy)(p->vecsz),
+ p->r, p->r + d[0].is, p->rio, p->iio);
+}
+
+static const madt adt_f_dft = {
+ applicable_f_dft, apply_f_dft, mkcld_f_dft, {10, 8, 0, 0}, "r2hc2-dft"
+};
+
+/*
+ * forward rdft2 via rdft
+ */
+static void k_f_rdft(R *rio, R *iio, const R *W, int n, int dist)
+{
+ int i;
+ R *pp = rio, *pm = rio + n * dist;
+ int im = iio - rio;
+
+ /* i = 0 and i = n */
+ {
+ E rop = pp[0], iop = pp[im];
+ pp[0] = rop + iop;
+ pm[0] = rop - iop;
+ pp[im] = K(0.0);
+ pm[im] = K(0.0);
+ pp += dist; pm -= dist;
+ }
+
+ /* middle elements */
+ for (W += 2, i = 2; i < n; i += 2, W += 2) {
+ E r0 = pp[0], r1 = pp[im], i0 = pm[0], i1 = pm[im];
+ E wr = W[0], wi = W[1];
+ E tr = r1 * wr + i1 * wi;
+ E ti = i1 * wr - r1 * wi;
+ pp[0] = r0 + tr;
+ pp[im] = i0 + ti;
+ pm[0] = r0 - tr;
+ pm[im] = ti - i0;
+ pp += dist; pm -= dist;
+ }
+
+ /* i = n/2 when n is even */
+ if (!(n & 1)) pp[im] = -pp[im];
+}
+
+static void apply_f_rdft(const plan *ego_, R *r, R *rio, R *iio)
+{
+ const P *ego = (const P *) ego_;
+
+ {
+ plan_rdft *cld = (plan_rdft *) ego->cld;
+ cld->apply((plan *) cld, r, rio);
+ }
+
+ {
+ int i, vl = ego->vl, n2 = ego->n / 2;
+ int ovs = ego->ovs, os = ego->os;
+ const R *W = ego->td->W;
+ for (i = 0; i < vl; ++i, rio += ovs, iio += ovs)
+ k_f_rdft(rio, iio, W, n2, os);
+ }
+}
+
+static problem *mkcld_f_rdft(const problem_rdft2 *p)
+{
+ const iodim *d = p->sz->dims;
+
+ tensor *radix = X(mktensor_1d)(2, d[0].is, p->iio - p->rio);
+ tensor *cld_vec = X(tensor_append)(radix, p->vecsz);
+ X(tensor_destroy)(radix);
+
+ return X(mkproblem_rdft_1_d) (
+ X(mktensor_1d)(d[0].n / 2, 2 * d[0].is, d[0].os),
+ cld_vec, p->r, p->rio, R2HC);
+}
+
+static const madt adt_f_rdft = {
+ applicable_f, apply_f_rdft, mkcld_f_rdft, {6, 4, 0, 0}, "r2hc2-rdft"
+};
+
+
+/*
+ * backward rdft2 via dft
+ */
+static void k_b_dft(R *rio, R *iio, const R *W, int n, int dist)
+{
+ int i;
+ R *pp = rio, *pm = rio + n * dist;
+ int im = iio - rio;
+
+ /* i = 0 and i = n */
+ {
+ E rop = pp[0], iop = pm[0];
+ pp[0] = rop + iop;
+ pp[im] = rop - iop;
+ pp += dist; pm -= dist;
+ }
+
+ /* middle elements */
+ for (W += 2, i = 2; i < n; i += 2, W += 2) {
+ E a = pp[0], b = pp[im], c = pm[0], d = pm[im];
+ E wr = W[0], wi = W[1];
+ E re = a + c, ti = a - c, ie = b - d, tr = b + d;
+ E rd = tr * wr + ti * wi;
+ E id = ti * wr - tr * wi;
+ pp[0] = re - rd;
+ pp[im] = ie + id;
+ pm[0] = re + rd;
+ pm[im] = id - ie;
+ pp += dist; pm -= dist;
+ }
+
+ /* i = n/2 when n is even */
+ if (!(n & 1)) { pp[0] *= K(2.0); pp[im] *= -K(2.0); }
+}
+
+static void apply_b_dft(const plan *ego_, R *r, R *rio, R *iio)
+{
+ const P *ego = (const P *) ego_;
+ {
+ int i, vl = ego->vl, n2 = ego->n / 2;
+ int ivs = ego->ivs, is = ego->is;
+ const R *W = ego->td->W;
+ R *rio1 = rio, *iio1 = iio;
+ for (i = 0; i < vl; ++i, rio1 += ivs, iio1 += ivs)
+ k_b_dft(rio1, iio1, W, n2, is);
+ }
+
+ {
+ plan_dft *cld = (plan_dft *) ego->cld;
+ /* swap r/i because of backward transform */
+ cld->apply((plan *) cld, iio, rio, r + ego->os, r);
+ }
+}
+
+static problem *mkcld_b_dft(const problem_rdft2 *p)
+{
+ const iodim *d = p->sz->dims;
+
+ return X(mkproblem_dft_d) (
+ X(mktensor_1d)(d[0].n / 2, d[0].is, 2 * d[0].os),
+ X(tensor_copy)(p->vecsz),
+ p->iio, p->rio, p->r + d[0].os, p->r);
+}
+
+static const madt adt_b_dft = {
+ applicable_b_dft, apply_b_dft, mkcld_b_dft, {10, 8, 0, 0}, "hc2r2-dft"
+};
+
+/*
+ * backward rdft2 via backward rdft
+ */
+static void k_b_rdft(R *rio, R *iio, const R *W, int n, int dist)
+{
+ int i;
+ R *pp = rio, *pm = rio + n * dist;
+ int im = iio - rio;
+
+ /* i = 0 and i = n */
+ {
+ E rop = pp[0], iop = pm[0];
+ pp[0] = rop + iop;
+ pp[im] = rop - iop;
+ pp += dist; pm -= dist;
+ }
+
+ /* middle elements */
+ for (W += 2, i = 2; i < n; i += 2, W += 2) {
+ E a = pp[0], b = pp[im], c = pm[0], d = pm[im];
+ E wr = W[0], wi = W[1];
+ E r0 = a + c, r1 = a - c, i0 = b - d, i1 = b + d;
+ pp[0] = r0;
+ pm[0] = i0;
+ pp[im] = r1 * wr - i1 * wi;
+ pm[im] = i1 * wr + r1 * wi;
+ pp += dist; pm -= dist;
+ }
+
+ /* i = n/2 when n is even */
+ if (!(n & 1)) { pp[0] *= K(2.0); pp[im] *= -K(2.0); }
+}
+
+static void apply_b_rdft(const plan *ego_, R *r, R *rio, R *iio)
+{
+ const P *ego = (const P *) ego_;
+
+ {
+ int i, vl = ego->vl, n2 = ego->n / 2;
+ int ivs = ego->ivs, is = ego->is;
+ const R *W = ego->td->W;
+ R *rio1 = rio, *iio1 = iio;
+ for (i = 0; i < vl; ++i, rio1 += ivs, iio1 += ivs)
+ k_b_rdft(rio1, iio1, W, n2, is);
+ }
+
+ {
+ plan_rdft *cld = (plan_rdft *) ego->cld;
+ cld->apply((plan *) cld, rio, r);
+ }
+}
+
+static problem *mkcld_b_rdft(const problem_rdft2 *p)
+{
+ const iodim *d = p->sz->dims;
+
+ tensor *radix = X(mktensor_1d)(2, p->iio - p->rio, d[0].os);
+ tensor *cld_vec = X(tensor_append)(radix, p->vecsz);
+ X(tensor_destroy)(radix);
+
+ return X(mkproblem_rdft_1_d) (
+ X(mktensor_1d)(d[0].n / 2, d[0].is, 2 * d[0].os),
+ cld_vec, p->rio, p->r, HC2R);
+}
+
+static const madt adt_b_rdft = {
+ applicable_b, apply_b_rdft, mkcld_b_rdft, {6, 4, 0, 0}, "hc2r2-rdft"
+};
+
+/*
+ * common stuff
+ */
+static void awake(plan *ego_, int flg)
+{
+ P *ego = (P *) ego_;
+ static const tw_instr twinstr[] = { {TW_FULL, 0, 2}, {TW_NEXT, 1, 0} };
+ AWAKE(ego->cld, flg);
+ X(twiddle_awake)(flg, &ego->td, twinstr, ego->n, 2, (ego->n / 2 + 1) / 2);
+}
+
+static void destroy(plan *ego_)
+{
+ P *ego = (P *) ego_;
+ X(plan_destroy_internal) (ego->cld);
+}
+
+static void print(const plan *ego_, printer * p)
+{
+ const P *ego = (const P *) ego_;
+ p->print(p, "(%s-%d%v%(%p%))", ego->slv->adt->nam,
+ ego->n, ego->vl, ego->cld);
+}
+
+static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
+{
+ const S *ego = (const S *) ego_;
+ P *pln;
+ const problem_rdft2 *p;
+ plan *cld;
+ const iodim *d;
+
+ static const plan_adt padt = {
+ X(rdft2_solve), awake, print, destroy
+ };
+
+ if (!ego->adt->applicable(p_, plnr))
+ return (plan *) 0;
+
+ p = (const problem_rdft2 *) p_;
+
+ cld = X(mkplan_d)(plnr, ego->adt->mkcld(p));
+ if (!cld) return (plan *) 0;
+
+ pln = MKPLAN_RDFT2(P, &padt, ego->adt->apply);
+
+ d = p->sz->dims;
+ pln->n = d[0].n;
+ pln->os = d[0].os;
+ pln->is = d[0].is;
+ X(tensor_tornk1) (p->vecsz, &pln->vl, &pln->ivs, &pln->ovs);
+ pln->cld = cld;
+ pln->td = 0;
+ pln->slv = ego;
+
+ /* approximately */
+ X(ops_madd)(pln->vl * ((pln->n/2 + 1) / 2), &ego->adt->ops,
+ &cld->ops, &pln->super.super.ops);
+
+ return &(pln->super.super);
+}
+
+static solver *mksolver(const madt *adt)
+{
+ static const solver_adt sadt = { mkplan };
+ S *slv = MKSOLVER(S, &sadt);
+ slv->adt = adt;
+ return &(slv->super);
+}
+
+void X(rdft2_radix2_register)(planner *p)
+{
+ unsigned i;
+ static const madt *const adts[] = {
+ &adt_f_dft, &adt_f_rdft,
+ &adt_b_dft, &adt_b_rdft
+ };
+
+ for (i = 0; i < sizeof(adts) / sizeof(adts[0]); ++i)
+ REGISTER_SOLVER(p, mksolver(adts[i]));
+}
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